Add latency constraint
Change-Id: If9936e995e5a40370965b9693ff7dda941d8c5b8
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/constraint/LatencyConstraint.java b/core/api/src/main/java/org/onlab/onos/net/intent/constraint/LatencyConstraint.java
new file mode 100644
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--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/constraint/LatencyConstraint.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2014 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onlab.onos.net.intent.constraint;
+
+import com.google.common.base.MoreObjects;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.intent.Constraint;
+import org.onlab.onos.net.resource.LinkResourceService;
+
+import java.time.Duration;
+import java.time.temporal.ChronoUnit;
+import java.util.Objects;
+
+/**
+ * Constraint that evaluates the latency through a path.
+ */
+public class LatencyConstraint implements Constraint {
+
+ // TODO: formalize the key for latency all over the codes.
+ private static final String LATENCY_KEY = "latency";
+
+ private final Duration latency;
+
+ /**
+ * Creates a new constraint to keep under specified latency through a path.
+ * @param latency latency to be kept
+ */
+ public LatencyConstraint(Duration latency) {
+ this.latency = latency;
+ }
+
+ public Duration getLatency() {
+ return latency;
+ }
+
+ @Override
+ public double cost(Link link, LinkResourceService resourceService) {
+ String value = link.annotations().value(LATENCY_KEY);
+
+ double latencyInMicroSec;
+ try {
+ latencyInMicroSec = Double.parseDouble(value);
+ } catch (NumberFormatException e) {
+ latencyInMicroSec = 1.0;
+ }
+
+ return latencyInMicroSec;
+ }
+
+ @Override
+ public boolean validate(Path path, LinkResourceService resourceService) {
+ double pathLatency = path.links().stream().mapToDouble(link -> cost(link, resourceService)).sum();
+ return Duration.of((long) pathLatency, ChronoUnit.MICROS).compareTo(latency) <= 0;
+ }
+
+ @Override
+ public int hashCode() {
+ return Objects.hash(latency);
+ }
+
+ @Override
+ public boolean equals(Object obj) {
+ if (this == obj) {
+ return true;
+ }
+
+ if (!(obj instanceof LatencyConstraint)) {
+ return false;
+ }
+
+ final LatencyConstraint that = (LatencyConstraint) obj;
+ return Objects.equals(this.latency, that.latency);
+ }
+
+ @Override
+ public String toString() {
+ return MoreObjects.toStringHelper(this)
+ .add("latency", latency)
+ .toString();
+ }
+}
diff --git a/core/api/src/test/java/org/onlab/onos/net/intent/constraint/LatencyConstraintTest.java b/core/api/src/test/java/org/onlab/onos/net/intent/constraint/LatencyConstraintTest.java
new file mode 100644
index 0000000..b9fa3ee
--- /dev/null
+++ b/core/api/src/test/java/org/onlab/onos/net/intent/constraint/LatencyConstraintTest.java
@@ -0,0 +1,124 @@
+/*
+ * Copyright 2014 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onlab.onos.net.intent.constraint;
+
+import com.google.common.testing.EqualsTester;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.onos.net.Annotations;
+import org.onlab.onos.net.DefaultAnnotations;
+import org.onlab.onos.net.DefaultLink;
+import org.onlab.onos.net.DefaultPath;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.net.resource.LinkResourceService;
+
+import java.time.Duration;
+import java.time.temporal.ChronoUnit;
+import java.util.Arrays;
+
+import static org.easymock.EasyMock.createMock;
+import static org.hamcrest.Matchers.closeTo;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+import static org.onlab.onos.net.DefaultLinkTest.cp;
+import static org.onlab.onos.net.DeviceId.deviceId;
+import static org.onlab.onos.net.Link.Type.DIRECT;
+
+public class LatencyConstraintTest {
+
+ private static final DeviceId DID1 = deviceId("of:1");
+ private static final DeviceId DID2 = deviceId("of:2");
+ private static final DeviceId DID3 = deviceId("of:3");
+ private static final PortNumber PN1 = PortNumber.portNumber(1);
+ private static final PortNumber PN2 = PortNumber.portNumber(2);
+ private static final PortNumber PN3 = PortNumber.portNumber(3);
+ private static final PortNumber PN4 = PortNumber.portNumber(4);
+ private static final ProviderId PROVIDER_ID = new ProviderId("of", "foo");
+ private static final String LATENCY_KEY = "latency";
+ private static final String LATENCY1 = "3.0";
+ private static final String LATENCY2 = "4.0";
+
+ private LatencyConstraint sut;
+ private LinkResourceService linkResourceService;
+
+ private Path path;
+ private Link link1;
+ private Link link2;
+
+ @Before
+ public void setUp() {
+ linkResourceService = createMock(LinkResourceService.class);
+
+ Annotations annotations1 = DefaultAnnotations.builder().set(LATENCY_KEY, LATENCY1).build();
+ Annotations annotations2 = DefaultAnnotations.builder().set(LATENCY_KEY, LATENCY2).build();
+
+ link1 = new DefaultLink(PROVIDER_ID, cp(DID1, PN1), cp(DID2, PN2), DIRECT, annotations1);
+ link2 = new DefaultLink(PROVIDER_ID, cp(DID2, PN3), cp(DID3, PN4), DIRECT, annotations2);
+ path = new DefaultPath(PROVIDER_ID, Arrays.asList(link1, link2), 10);
+ }
+
+ /**
+ * Tests the path latency is less than the supplied constraint.
+ */
+ @Test
+ public void testLessThanLatency() {
+ sut = new LatencyConstraint(Duration.of(10, ChronoUnit.MICROS));
+
+ assertThat(sut.validate(path, linkResourceService), is(true));
+ }
+
+ /**
+ * Tests the path latency is more than the supplied constraint.
+ */
+ @Test
+ public void testMoreThanLatency() {
+ sut = new LatencyConstraint(Duration.of(3, ChronoUnit.MICROS));
+
+ assertThat(sut.validate(path, linkResourceService), is(false));
+ }
+
+ /**
+ * Tests the link latency is equal to "latency" annotated value.
+ */
+ @Test
+ public void testCost() {
+ sut = new LatencyConstraint(Duration.of(10, ChronoUnit.MICROS));
+
+ assertThat(sut.cost(link1, linkResourceService), is(closeTo(Double.parseDouble(LATENCY1), 1.0e-6)));
+ assertThat(sut.cost(link2, linkResourceService), is(closeTo(Double.parseDouble(LATENCY2), 1.0e-6)));
+ }
+
+ /**
+ * Tests equality of the instances.
+ */
+ @Test
+ public void testEquality() {
+ LatencyConstraint c1 = new LatencyConstraint(Duration.of(1, ChronoUnit.SECONDS));
+ LatencyConstraint c2 = new LatencyConstraint(Duration.of(1000, ChronoUnit.MILLIS));
+
+ LatencyConstraint c3 = new LatencyConstraint(Duration.of(2, ChronoUnit.SECONDS));
+ LatencyConstraint c4 = new LatencyConstraint(Duration.of(2000, ChronoUnit.MILLIS));
+
+ new EqualsTester()
+ .addEqualityGroup(c1, c2)
+ .addEqualityGroup(c3, c4)
+ .testEquals();
+ }
+}